Tidal effects on net ecosystem exchange of carbon in an estuarine wetland

H. Guo; A. Noormets; B. Zhao; J. Chen; Ge Sun; Y. Gu; B. Li; J. Chen

doi:10.1016/j.agrformet.2009.06.010

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Tidal effects on net ecosystem exchange of carbon in an estuarine wetland

Informally Refereed

Authors:

H. Guo, A. Noormets, B. Zhao, J. Chen, Ge Sun, Y. Gu, B. Li, J. Chen

Year:

2009

Type:

Scientific Journal

Station:

Southern Research Station

DOI:

https://doi.org/10.1016/j.agrformet.2009.06.010

Source:

Agricultural and Forest Meteorology 149:1820-1828.

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Abstract

One year of continuous data from two eddy-flux towers established along an elevation gradient incoastal Shanghai was analyzed to evaluate the tidal effect on carbon flux (Fc) over an estuarine wetland.The measured wavelet spectra and cospectra of Fc and other environmental factors demonstrated thatthe dynamics of Fc at both sites exhibited a tidal-driven pattern with obvious characteristics at scalesbetween 10 and 20 days (256–512-h). Environmental factors exerted major controls on the carbonbalance at finer temporal scales. Fc was more sensitive to tides at the low-elevation site than at the highelevationsite. Overall, the mean nighttime Fc during spring tides was lower than that during neap tides,indicating suppressed ecosystem respiration under inundation. Larger differences were observed at thelow-elevation site due to longer inundation durations. In contrast, daytime Fc was more variable sinceplants reacted differently in different growth periods and under different tidal elevations. Theamplitudes of diurnal Fc during tidal periods were larger than those reported for other wetland types,implying a great potential for future carbon sequestration. Whilst tides would also transport organicmatter to nearby estuaries and hence may incur carbon emission in the receiving ecosystems. Thus,further study on lateral carbon transport is required to investigate the tidal effect on the carbon sink/source role of the wetland.

Keywords

estuarine wetland, carbon flux, tidal elevationm eddy covariance, spectral analysis, respiration

Citation

Guo, H.;Noormets, A. ; Zhao, B.;Chen, J.;Sun, G. ;Gu, Y.;Li, B.;Chen, J. 2009. Tidal effects on net ecosystem exchange of carbon in an estuarine wetland. Agricultural and Forest Meteorology 149:1820-1828.